Understanding water-metal interactions is central to disciplines spanning catalysis, electrochemistry, and atmospheric science. Monolayer ice phases are well established on hydrophilic surfaces, where strong water-substrate interactions stabilize ordered hydrogen-bond networks. In contrast, their formation on hydrophobic metals has been deemed thermodynamically unfavorable, with water typically assembling into amorphous films, three-dimensional crystallites, or interlocked bilayer ice. Here, we demonstrate the synthesis of a monolayer ice phase on the hydrophobic Au(111) surface using a low-energy-electron-assisted growth method. Combined experimental characterizations including low-energy electron diffraction, angle-resolved photoemission spectroscopy, and X-ray photoelectron spectroscopy, complemented by first-principles calculations, prove that the monolayer ice phase composes of intact water molecules. This approach provides a generalizable strategy for stabilizing ordered two-dimensional ice on inert substrates and offers new insight into the interplay between water and low-energy electrons at hydrophobic interfaces.

Halogens, known for their diatomic molecular structures, typically do not form extended covalent materials. The development of 2D elemental materials from halogens is therefore significant for both fundamental research and practical applications. Here, we report the realization of a monolayer iodine sheet, namely iodinene, with multiple exotic properties. Using angle-resolved photoemission spectroscopy, scanning tunneling microscopy, and first-principles calculations, we show that iodinene hosts 2D topological crystalline insulator states, a long-sought topological state previously observed only in 3D materials. Moreover, iodinene is exceptionally stable under ambient conditions. By applying a tensile strain of 48%, we realize two nearly flat bands with robust topological edge states in between, paving the way for the design and fabrication of tunable topological and spintronic devices.

The catalytic performance of supported rare-earth oxide subnanoclusters is closely correlated with their electronic structure, yet direct experimental evidence on how the support coordination field modulates 5d orbitals and d-π* back-donation remains scarce. Here, we constructed La-O subnanoclusters in a nitrogen-vacancy coordination field of graphitic carbon nitride via ionic liquid -induced structural distortion. X-ray photoelectron spectroscopy revealed negative shifts in La 3d and O 1s binding energies, indicating the transfer of electron from the defective g-C3N4 matrix to the La-O clusters. La L3-edge X-ray absorption near-edge structure showed a negative shift of the absorption edge, indicative of downshifted unoccupied La 5d states. Density functional theory calculations further revealed that this coordination-field modulation narrowed the 5d orbital energy gap and increased the density of states near the Fermi level, endowing the La-O subnanoclusters with enhanced d-π* back-donation capability. This lowered the energy barrier of the rate-determining step in the alcoholysis of glycerol with urea, increasing the glycerol carbonate yield from 30.2% for the pristine counterpart to 93.3% with 97.8% selectivity. This work provided direct experimental insights and a feasible strategy for the rational design of supported rare-earth subnanocluster catalysts via support defect engineering.

Achieving a balance between high yield stress and superb sedimentation stability remains a great challenge for magnetorheological (MR) fluids. Developing nanocomposites by integrating magnetic particles with low-dimensional nanomaterials is an effective strategy to address this issue. In this study, Fe3O4/WS2 nanocomposites were designed and synthesized involving the hydrothermal growth of Fe3O4 nanoparticles onto the exfoliated WS2 nanosheets. A detailed characterization was conducted using a range of analytical tools such as SEM, XRD, Raman, XPS and VSM to confirm the successful construction of Fe3O4/WS2 nanocomposites. The MR fluid was subsequently prepared by dispersing the resulting Fe3O4/WS2 nanocomposites into silicone oil. The MR properties were measured under different magnetic field intensities in both steady shear and oscillatory shear modes. The rheological parameters including shear viscosity, shear stress, storage modulus and loss modulus demonstrated a strong dependence on the applied magnetic field intensity. The mechanism involved the formation of more extensive and robust field-induced chain-like structures with increasing field strength. Finally, the sedimentation stability was quantitatively monitored over time and it was revealed the Fe3O4/WS2-based MR fluid exhibited possessed significantly improved sedimentation stability relative to the conventional carbonyl iron particles.

Controlled drug delivery has demonstrated its great potential to alleviate the unpleasant side effects triggered by chemotherapeutic drugs through improving treatment efficacy in cancer cells while decreasing the adverse effects on normal cells. Herein, hexagonal MgAl-layered double hydroxide (Mg-Al LDH) nanoplates were fabricated by a facile hydrothermal strategy, which were developed as a promising pH-responsive drug delivery system for cancer treatment. The MgAl-LDH nanoplates possessed unique features including well-defined hexagonal morphology, uniform particle size, rough surface, typical mesoporous structure, and high specific surface area. The MgAl-LDH nanoplates exhibited a high drug loading capability of 0.36 mg/mg using non-anionic doxorubicin hydrochloride (DOX) as a classical anticancer model drug. The loaded DOX displayed a sustained and pH-controlled release characteristic with sufficient release of 91.4% and 69.9% under acidic pH values (4.0, 5.5) and suppressed release of 37.8% at a neutral pH level (7.4) after 48 h of release. Furthermore, the developed MgAl-LDH nanoplates displayed good biocompatibility without any obvious cytotoxicity to human breast cancer cells (MCF-7), and DOX-loaded MgAl-LDH exerted the effects of significant suppression of cell proliferation and induction of apoptosis in regions of high concentration.

Bulk two dimensional (2D) superconductivity has gained considerable attention due to its intricate interplay between symmetry breaking, nontrivial topology, 2D phase fluctuations, and unconventional superconductivity. However, certain intercalated layered superconductors, despite their short c-axis superconducting coherence length, have been misclassified as anisotropic three-dimensional (3D) superconductors. Here, we investigate (Li,Fe)OHFeSe superconductors with varying degrees of interlayer misalignment, revealing sample-dependent superconducting dimensionality while consistently observing Berezinskii Kosterlitz Thouless (BKT) transitions. To resolve this discrepancy, we develop an extended 2D Tinkham model that quantitatively captures the blurring effects induced by interlayer misalignment. We further demonstrate the validity of this model in both (Li,Fe)OHFeSe and cetyltrimethyl ammonium (CTA+) intercalated (CTA)0.5SnSe2 superconductors, highlighting its broad applicability. This work provides valuable insights into bulk 2D superconductivity and establishes an extended 2D Tinkham model for quantitatively extracting intrinsic superconducting properties in intercalated layered superconductors, particularly those exhibiting significant interlayer misalignments.

Nitrogen, the most abundant element in Earth’s atmosphere, exists as a diatomic gas under standard temperature and pressure. In the two-dimensional (2D) limit, atomically thin nitrogen, termed nitrogene, has been theoretically predicted to form crystalline materials with various polymorphic configurations, exhibiting diverse chemical and physical properties. However, the synthesis of nitrogene has remained elusive due to the strong nitrogen-nitrogen triple bonds. Here, we report experimental evidence of the formation of nitrogen-based crystalline structures compatible with nitrogene on silver surfaces via ion-beam-assisted epitaxy. Through a combination of scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and first-principles calculations, we demonstrate that the nitrogene-like structure adopts a puckered honeycomb lattice. Notably, our calculations predict a nitrogene band gap of up to 7.5 eV, positioning it as a promising candidate for ultraviolet optoelectronic devices and high-κ dielectric applications. Atomically thin nitrogen crystals, termed nitrogene, have been theoretically predicted, but their synthesis has remained elusive so far. Here, the authors report experimental evidence of the formation of nitrogen-based crystalline structures compatible with nitrogene on Ag(100) surfaces via ion-beam-assisted epitaxy.

Sub‐1‐nm nanowires (NWs) with fascinating physicochemical properties have demonstrated remarkable potential for applications across various fields. However, it remains a great challenge to prepare sub‐1‐nm NWs with near‐infrared (NIR) absorption characteristics and explore their optoelectronic applications, so far. Herein, a novel cation‐exchange strategy in N, N‐dimethylformamide (DMF) solvent is introduced to synthesize sub‐1‐nm PbSe NWs, starting from sub‐1‐nm ZnSe NWs. Theoretical calculations and nuclear magnetic resonance (NMR) measurements have confirmed that the cation exchange reaction in DMF effectively reduces the barriers for Zn 2+ extraction and Pb 2+ introduction compared to the conventional toluene/methanol system. Notably, the resulting sub‐1‐nm PbSe NWs exhibit a strong absorption peak at ≈940 nm. Leveraging their unique NIR absorption features and superior carrier transport properties, self‐powered photoelectrochemical‐type (PEC) photodetectors is fabricated based on sub‐1‐nm PbSe NWs embedded in polyvinylidene fluoride (PVDF) composite films. These photodetectors demonstrated exceptional photoresponse performance under 940 nm illumination (8.0 mW cm −2 ), with a typical on/off ratio of 4860, a detectivity of 4.65 × 10 11 Jones, and a responsivity of 113 mA W −1 . This work provides a new approach for developing and investigating NIR photoactive sub‐1‐nm semiconductor NWs with broad application prospects.

3D‐printable photonic crystals are widely utilized in sensors, painting decoration, and information encryption. The development of photonic inks capable of forming complex shapes and exhibiting flexible color changes enables the fabrication of structural‐color devices with unique structures and specialized functions, while achieving collaborative control over 3D printability and dynamic color‐changing function remains a significant challenge. Here, printable and thermosensitive photonic inks are demonstrated through the co‐assembly of hydroxypropyl cellulose (HPC) and hydroxyethyl acrylate into cholesteric liquid crystals. The semi‐interpenetrating network created by HEA polymerization, along with the hydrogen bonding between the co‐phases, facilitates the 3D printing of complex objects. Moreover, this network maintains the cholesteric phase structure while reducing the phase separation of HPC, enabling the manipulation of varying degrees of color change, with sensitivities ranging from 6.4 to 3.0 nm °C −1 . Through 3D printing, these photonic inks can be utilized to create both 2D and 3D objects with dynamic thermochromic properties. This work offers a simple and instructive strategy for developing flexible and responsive photonic materials.

It is essential to remove the oil spills from the water surface and protect the marine environment and organisms. The commercial approaches for oil-water separation are seriously constrained by the high cost, low removal efficiency and potential secondary pollution. In the present work, we have reported a cost-effective, recyclable and environmental-friendly magnetorheological (MR) fluid for fast removal of oil spills from water surface. Successful fabrication of superhydrophobic NiFe2O4 nanospheres was achieved through a solvothermal strategy combining with a post-treatment process with octadecanoic acid. The synthesized NiFe2O4 nanospheres exhibited superparamagnetism, high saturation magnetization of 64.4 kA/m, large specific surface area of 12.9 m2/g, and small average pore diameter of 10.9 nm, which were strongly recommended as a dispersed phase for acquiring a high-performance MR fluid. The developed NiFe2O4 nanospheres-based MR fluid demonstrated the enhanced magnetic field-dependent rheological and viscoelastic properties as well as a remarkable sedimentation stability with a sedimentation ratio of 82.5 %. More importantly, such magnetic fluid was fully capable of realizing the rapid and efficient separation of oil spills from water surface and the maximum removal efficiency was determined to be about 96.3 %. Therefore, this work provides a promising candidate for oil spills clean-up with the unique characteristics of high oil removal efficiency, fast recovery and good recyclability.

Abstract Symmetry elegantly governs the fundamental properties and derived functionalities of condensed matter. For instance, realizing the superconducting diode effect (SDE) demands breaking space-inversion and time-reversal symmetries simultaneously. Although the SDE is widely observed in various platforms, its underlying mechanism remains debated, particularly regarding the role of vortices. Here, we systematically investigate the nonreciprocal transport in the chiral type-I superconductor NbGe2. Moreover, we induce type-II superconductivity with elevated superconducting critical temperature on the artificial surface by focused ion beam irradiation, enabling control over vortex dynamics in NbGe2 devices. Strikingly, we observe negligible diode efficiency (Q < 2%) at low magnetic fields, which rises significantly to Q ~ 50% at high magnetic fields, coinciding with an abrupt increase in vortex creep rate when the superconductivity of NbGe2 bulk is suppressed. These results unambiguously highlight the critical role of vortex dynamics in the SDE, in addition to the established symmetry rules.

Flat-band materials have garnered extensive attention due to their captivating properties associated with strong correlation effects. While flat bands have been discovered in several types of 2D materials, their existence in 1D systems remains elusive. Here, we propose a 1D frustrated lattice, specifically the 1D zigzag lattice, as a platform for hosting flat bands. This lattice can be experimentally realized by growing CuTe chains on Cu(111). The presence of flat bands was confirmed by tight-binding model analysis, first-principles calculations, and angle-resolved photoemission spectroscopy measurements. In addition, we discovered a temperature-driven phase transition at approximately 250 K. Detailed analyses demonstrate that the system has a Tomonaga-Luttinger liquid behavior, accompanied by spin-charge separation effects. Our work unveils new prospects for investigating strongly correlated electron behaviors and topological properties in the 1D limit.

Although metal halide perovskite (MHP) materials are promising candidates for direct X-ray detection, the surface and internal defects of perovskite polycrystalline thick films lead to severe noise current and poor device stability. Herein, a phenylethylammonium (PEA+) cladding layer was integrated with 3D CsPbBr3 grains, forming 3D/2D core-shell CsPbBr3 perovskite microcrystals. The PEA+, acting as the A-site cation, is able to passivate the surface defects, while the forming 2D perovskite cladding layer inhibits ion migration within CsPbBr3 grains. The blade-coated polycrystalline 3D/2D core-shell CsPbBr3 perovskite thick film exhibits a reduced trap density from 4.32 x 1010 cm(-3) to 4.26 x 109 cm(-3) compared to conventional CsPbBr3 film, with ion migration activation energy increasing from 123 meV to 210 meV. Consequently, the obtained perovskite X-ray detector exhibits a high sensitivity of 29,460 mu C Gy(-1) air cm(-2) and a low detection limit of 84 nGyairs(-1) (50 keV X-ray photon energy), and the detector maintains long-term operational stability with a dark current drift as low as 4.12 x 10(-5) nA mm(-1) s(-1) V-1. Furthermore, we integrated the 3D/2D core-shell polycrystalline CsPbBr3 with a TFT chip (64 x 64 array) and successfully obtained a clear and high-contrast X-ray image of a mouse's paw exhibiting a spatial resolution of 2.5 lp mm(-1).

Designing lattice-distortion-induced perovskite materials to disrupt intracellular soNa(+) homeostasis via targeting sodium-potassium ATPase (Na+/K+ ATPase) has emerged as a promising therapeutic strategy in cancer treatment. However, precise manipulation of Na+ balance to achieve targeted anti-tumor effects remains challenging. Here, a lattice-distorted and oxygen vacancy-rich niobium-based perovskite, NaNbO3 (NNOx), is synthesized by utilizing the piezo-catalytic and photothermal properties of NNOx, and a cascade regulation of Na+/K+ ATPase is achieved. Particularly, under ultrasound and near-infrared II laser irradiation, NNOx not only releases exogenous Na+ to elevate local intracellular Na+ concentrations but also efficiently generates reactive oxygen species, inducing mitochondrial damage and impairing ATP synthesis in tumor cells. This mitochondrial dysfunction dramatically reduces Na+/K+ ATPase activity, impairs cellular Na+ efflux, and further exacerbates intracellular Na+ accumulation. Consequently, the severe ionic imbalance leads to rapid osmotic swelling and bubble formation, triggering pyroptotic cell death and robust anti-tumor immune responses. In vitro and in vivo studies demonstrate that NNOx efficiently suppresses tumor growth and activates potent anti-tumor immunity, highlighting an innovative strategy for ionic disruption-induced pyroptosis and immunogenic cell death. This approach provides valuable insights for future ionic homeostasis-targeted cancer immunotherapy.

The kagome lattice is a versatile platform for investigating correlated electronic states. However, its realization in two-dimensional (2D) semiconductors for tunable device applications is still challenging. An alternative strategy to create kagome-like bands is to realize a coloring-triangle (CT) lattice in semiconductors through a distortion of a modified triangular lattice. Here, we report the observation of low-energy kagome-like bands in a semiconducting 2D transition metal chalcogenide-Cr8Se12 with a thickness of 7 atomic layers-which exhibits a CT lattice and a bandgap of 0.8 eV. The Cr-deficient layer beneath the topmost Se-full layer is partially occupied with 2/3 occupancy, yielding a √3 × √3 Cr honeycomb network. Angle-resolved photoemission spectroscopy measurements and first-principles investigations reveal the surface kagome-like bands near the valence band maximum, which are attributed to topmost Se pz orbitals modulated by the honeycomb Cr.

Structural topology and symmetry of a two-dimensional (2D) network play pivotal roles in defining its electrical properties and functionalities. Here, a binary buckled honeycomb lattice with C3v symmetry, which naturally hosts topological Dirac fermions and out-of-plane polarity, is proposed. It is successfully achieved in a group IV-V compound, namely monolayer SiP epitaxially grown on Ag(111) surface. Combining first-principles calculations with angle-resolved photoemission spectroscopy, the degeneration of the Dirac nodal lines to points due to the broken horizonal mirror symmetry is elucidated. More interesting, the SiP monolayer manifests metallic nature, which is mutually exclusive with polarity in conventional materials. It is further found that the out-of-plane polarity is strongly suppressed by the metallic substrate. This study not only represents a breakthrough of realizing intrinsic polarity in 2D metallic material via ingenious design but also provides a comprehensive understanding of the intricate interplay of many exotic low-dimensional quantum phenomena.

Immune checkpoint inhibitors have demonstrated remarkable efficacy across various cancer types. However, immune-related adverse events (irAEs) pose a significant challenge in immunotherapy, particularly the associated pneumonia as the primary adverse reaction, which can lead to irreversible pulmonary fibrosis. Additionally, monotherapy with programmed death ligand (PD-L1) inhibitors has shown limited effectiveness. Therefore, to improve the response rate of immunotherapy and reduce pulmonary fibrosis, this study designed and prepared an intelligent nanodrug based on dendritic mesoporous silica nanoparticles (DMSNs) loaded with a sono-sensitive agent protoporphyrin IX (PpIX). Additionally, a reactive oxygen species (ROS) sensitive linker is used to attach the immunotherapeutic drug PD-L1 inhibitor (aPD-L1) to DMSNs via covalent bonds. The external ultrasound (US) activates PpIX to generate ROS, which breaks the linker to release aPD-L1 to induce sonodynamic therapy (SDT) and immunotherapy. This sono-immnotherapy approach demonstrated excellent outcomes in tumor inhibition, eliciting immune responses, and reducing pulmonary fibrosis. Overall, this study offers a new, efficient, and safe method for breast cancer treatment, and expands the application of immunotherapy.

Magnetorheological (MR) fluids have been extensively studied and utilized in various fields but are still restricted for their broad applications owing to the relatively poor sedimentation stability. Herein, mulberry-like NiFe2O4 nanospheres were fabricated via a facile solvothermal route to fight against the sedimentation challenge. Different analytical approaches were employed to thoroughly characterize the fabricated mulberry-like NiFe2O4 nanospheres. The resultant NiFe2O4 nanospheres were suspended in silicone oil to produce the model MR suspension and its magneto-responsive properties and sedimentation stability were investigated in detail. It was revealed that the NiFe2O4 nanospheres-based suspension demonstrated sufficient MR responses, which can be interpreted as evidence that the increased rheological and viscoelastic properties were observed as the magnetic field intensity increased. Furthermore, the designed novel MR suspension demonstrated a superior sedimentation stability in comparison with the carbonyl iron particles-based MR system, which was positive in the practical application of MR fluids to microfluidic devices.

Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear microscopic explanation. Here, using high-resolution scanning tunneling microscopy, we studied single vortex pinning induced by point defect in layered FeSe-based superconductors. We found the defect-vortex interaction drives low-energy vortex bound states away from EF, creating a "mini" gap that effectively lowers the system energy and enhances pinning. By measuring the local density of states, we directly obtained the elementary pinning energy and estimated the pinning force via the spatial gradient of pinning energy. The results are consistent with bulk critical current measurement. Furthermore, we showed that a general microscopic quantum model incorporating defect-vortex interaction can naturally capture our observation. It suggests that the local pairing near pinned vortex core is actually enhanced compared to unpinned vortex, which is beyond the traditional understanding that nonsuperconducting regions pin vortices. Our study thus unveils a general microscopic mechanism of vortex pinning in superconductors and provides insights for enhancing the critical current of practical superconductors.